Arthrodiastasis in the management of Perthes disease: a systematic review

Reliability and Validity of Visual Estimation of Femoral Head Hypoperfusion on Perfusion MRI in Legg-Calve-Perthes Disease

BACKGROUND

Assessing the severity of Legg-Calve-Perthes disease is important for treatment decision-making and determining prognosis. Perfusion magnetic resonance imaging (MRI) scans have improved our ability to assess femoral head hypoperfusion, and the use of an image analysis software called HipVasc (Scottish Rite for Children, Dallas TX) has allowed precise quantification for research purposes. In the clinical setting, using HipVasc software is not practical, and visual estimation is used to assess hypoperfusion. Currently, the reliability of visual estimation is unknown. The purpose of this study was to determine the reliability and validity of visual estimation of hypoperfusion on perfusion MRI and compare the results to measurements obtained with the HipVasc software.

METHODS

Fourteen pediatric orthopaedic surgeons, divided into 4 groups, participated in this study. Each surgeon completed a 30-minute in-person training on HipVasc before proceeding. Stratified by category of severity, 122 MRIs were randomly assigned to 1 of the 4 groups so that each group member measured the same set of ∼30 MRIs. Each surgeon documented their visual estimation of hypoperfusion first, then used HipVasc to measure the hypoperfusion and recorded their results. Interobserver reliability was assessed at the group level by calculating the intraclass correlation coefficient.

RESULTS

Good correlation and reliability was found between the visual estimate and HipVasc measurements with an overall mean intraclass correlation coefficient of 0.87 and mean Pearson coefficient of 0.90. The mean interobserver reliability of visual estimation was 0.84. Observers had a tendency to overestimate hypoperfusion with visual estimation.

CONCLUSIONS

This study demonstrates the reliability and validity of visual estimation as a clinically applicable method for determining femoral head hypoperfusion. Our study is the first to measure the reliability of visual estimation and HipVasc with a large cohort of clinicians, specifically pediatric orthopaedic surgeons with varied experience in graphical software analysis. We recommend using visual estimation as a clinically applicable method to make treatment decisions, and its accuracy is comparable to HipVasc software analysis.

LEVEL OF EVIDENCE

Level III-diagnostic.

Surgical Treatments for Legg-Calvé-Perthes Disease: Comprehensive Review

Background

Legg-Calvé-Perthes disease (LCPD) is a common public health problem that usually occurs between the ages of 4 and 8 years, but it can occur between the ages of 2 and 15 years. This condition occurs due to the interruption of blood supply to the femoral head. Up to now, different surgical and nonsurgical treatments, including femoral varus osteotomy, innominate osteotomy, pelvic osteotomies, triple osteotomy, Chiari osteotomy, and shelf acetabuloplasty, have been suggested for noncontainable LCPD hips.

Objective

The aim of this comprehensive review was to investigate the various surgical techniques used for LCPD.

Methods

An advanced electronic search of the English-language literature was performed from October 8 to 14, 2020. The electronic databases PubMed, MEDLINE, Web of Science, Embase, Ovid, and Google scholar were searched using appropriate search terms. A manual search of references also was performed. After retrieving the studies, duplicates were removed, and the remining studies were screened based on the title, abstract, and full text. The quality of the selected articles was assessed, and the required data were extracted from eligible articles.

Results

A total of 22 studies were included in the review. Based on the results of the reviewed studies, there are three main factors that influence the treatment outcomes in patients with Perthes disease. These factors are onset age, femoral head involvement severity, and treatment method. The disease has a poor prognosis in children over 8 years old, but this group of patients can also benefit from advanced surgical methods. In patients aged less than 6 years, the disease has a generally good prognosis, but in those aged between 6 and 8 years, its prognosis is variable. Thus, the need for surgical intervention requires close observation of signs. Once any head signs are observed, dynamic arthrography is beneficial before choosing the treatment approach.

Conclusions

This review provides clinicians with a brief guideline for the treatment of patients with LCPD.

Role of Arthrodiastasis Using Hinged Monolateral External Fixator Without Soft Tissue Release in Advanced Stage of Legg-Calve-Perthes Disease

Purpose

Presentation with the advanced stage of Legg-Calve-Perthes disease (LCPD) carries a poor prognosis, regardless of the treatment that the patient receives. The aims of this study are to assess the clinical and radiological outcomes of arthrodiastasis in advanced cases of LCPD using a hinged monolateral external fixator without soft tissue release and to raise safety issues regarding its low rate of complications.

Patients and Methods

Six patients with LCPD who were classified as lateral pillar types B and C and were operated on in our department were included in this retrospective study. Data collected from medical files and X-ray measurements were retrospectively reviewed.

Results

A total of six male patients were included in this analysis. The mean age at onset of symptoms was 8.5 years (range 7-10 years). The mean follow-up period was 46 months (range 40-50 months). Five cases were Herring C and one case was Herring B at presentation. The average distraction time was 8 days (range 7-9) and the average duration of external fixator application was 3.1 months (range 2.5-3.5 months). The range of motion of the hip in flexion, abduction and internal rotation were improved postoperatively. Pain score and limping were also improved. At the final follow-up, the mean sphericity deviation score was 10.6. The mean epiphyseal index was improved from 19.3% to 23.8%. In addition, the mean cervical index improved from 99.7% to 89.7% at the last follow-up. Femoral fractures, pin loosening, mechanical failure of the fixator, chondrodiastasis, and hip subluxation were not seen in this group of patients.

Conclusion

Arthrodiastasis with a hinged monolateral external fixator without soft tissue release improved both the clinical and radiological outcomes in this group of patients.